Floating toolholder



A 1943' J. A. HOWARD 2,327,897

FLOATING TOOL HOLDER Filed March 18, 1942 2 Sheets-Sheet 1 Inventor Aug. 24, 1943. J. HOWARD 2,327,897 FLOATING TOOL HOLDER I Filed March 18, 1942 2 Sheets-Sheet 2 Inventor Patented Aug. 24, 1943 U E V STATES .ITIDQATIJNG 'roonnonimrt v V Jnseph'Howard,.21oscQe,.-:Galif; I a sas inate 18, 194,2, ScriaLNo. 435,225

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invention relates to. irnproyements in too! holders for use espracially, although .notneces- .sarilY. n turret, lathes,

, The-invention; is designed .witn the, particul r object in View of providing a. simply constructed,

efficient, floating tool holder for reamers adapted for maintaining the reamer accurately centered in; the. hole being reamed and which may be used-with ,othe rtools. such as drills and taps. and

in other types of lathes. i

Other and subordinate objects arealso comprehended ;.bymy invention, all of which, together with the precise natureof myirnprovemerits; will be readily imderstood when the succeeding description and-claimsare-readwith reference to the drawings accompanying and forming part of thisspecification r I In. saiddrawings: V

Figure 1 is a view in side elevation of the preferred embodiment of my invention.

Figure 2 is a view in longitudinal section drawn to an enlarged scale.

Figure 3 is a View in front elevation.

Figure 4 is a View in front elevation of the bar detached.

Figure 5 is a view in transverse section taken on the line 5-5 of Figure 4, and T Figure 6 is a similar View of a modification of the invention.

Referring to the drawings by numerals, my improved tool holder in its preferred embodiment disk-like, concentric head 2 externally threaded, 5

as at 3, the head having a flat front face 4 perpendicular to the axis of the shank I.

An internally threaded clamping ring 5 is turned onto the head 2 and is provided in front of the head 2 with an internal, annular, front ed e flange t5 disposed at a right angle to the body of the ring for clamping coaction with the front face 4 of said head for a purpose presently seen. Sockets 1 are provided in the ring for use in turning the same on and off the head 2 with a tool such as a spanner wrench.

Clamped between the flange 5 and the front face 4 of the head 2 is a barii designed to extend diametrically of the head and to fit flat against said face t, said bar having reduced ends 8' fitting behind the flange 5 whereby said bar may be clamped between the face 4 of the head 2 and said flange by turning the ring 5 onto the head. Thebar 8 is shorter than the diameter of the head 2 to provide for endwise shifting of the ame: r lative tothehead for a pu pos presently clear- The bar dsis provided with a central-inwardly taperingbore 9. in which is frictionally fitted a center i0 tapered. forwardlyat any dc sired. angle, to a point and; extending forwardly of s'aidbar: particular. feature of my invention is that the bar 8 is formedmith a longitudinally convexfront face i lpreferably, as shown-in-Eigurea-.3, land 5,,proivided with beveled side edges .LZ, fThe.,-front,face; Lt of the bar .8 is. precision formedin an arc-, if theholder be mounted ina turret lathe} of the same radiusasthe are in whichthe turret-of thelathe swings. The bar 8 carries a collet I 3 extending forwardly therefrom axially thereof and into :which the center ii .0, extends part way.

18 in the collet, it being understood that the shank of the reamer is designed to fit in the col- 25 let. The rear end of the collet I3 is formed with a concave diametrical groove therein, as at I9, said groove being formed longitudinally and transversely to conform to the shape of the front face ll ofthe bar 8. The flange [5 of the collet l3 has formed therein a pair of diametrically opposite slots 28 elongated radially of the flange and for accommodating a pair of lag screws 2| turned into threaded bores 22 provided in the face H of the bar 8. The screws 2| are smaller in diameter than the width of the slots 20 so that with said screws loosened, the collet may float on the bar 8. In the modification of the invention shown in Figure 6, the front face 23 of the baris formed transversely in the arc of a circle. The collet when used with this form of bar, as will be understood. will be correspondingly modified as regards the diametrical groove therein.

In setting the described holder in a turret lathe, the shank I is pushed into a socket of the turret 24 of the lathe, not shown, with the bar8 disposed horizontally. The shank I should be secured in the turret 24 in a position such that the longitudinal curve of the front face H of the bar 8 will swing concentrically about the axis of the turret when the latter swings around. After the shank l is thus positioned in the turret 24, the collet I 3 is detached, the ring 5 loosened to free the bar 8, and the turret moves forwardly to enter the center 10 in the hole to be reamed. With slight pressure on the turret, the center ID will locate itself and hence the bar 8 on center to maintain the center In and bar 8 in the centered position, after which the collet l3 may be attached to the bar 8, with the screws loosened, and the shank of the reamer l8 may be secured in the collet l3 slightly forward of the center l0 to permit the collet l3 to ride or float on the bar 8. The longitudinal curvature of the face I I of the bar 8 coacts with the groove IS in the collet to cam the collet and hence the reamer l8 into centered position relative to the hole. The transverse beveled edges [2 of the bar 8, or, the arcuate form of said bar, as in the modified embodiment, coacts with said groove to lift the collet and hence the tail end of the reamer' into line with a minimum of pressure exerted against.

the reamer.

As an optional use of the described. holder, in working with small reamers, after the bar 8 has been centered relative to the hole in the manner already described, the center 10 may be detached from the bar 8 and the shank of the reamer shoved back into the shank I, through said bar 8, to float in said shank I.

The foregoing will, it is believed, suffice to impart a clear understanding of my invention without further explanation.

Although the invention has been described relative to the hole. The ring 5 is then tightened on one end thereof, having a front face perpendicular to the axis of said shank, a bar fitting flat against said face to extend across the same, and having a longitudinally arcuate front face and side edges converging toward said face, a center extending forwardly from said bar centrally thereof for insertion in a hole to be reamed to thereby axially align the bar with said hole, means to fasten said bar to said head in axially aligned position, a collet for holding a reamer with the tail end on said center, said collet inter.-

V fitting with the front face and sides of said bar,

herein in specific terms, it is to be understood that the present disclosure is illustrative rather than restrictive, and that other modifications than described may be resorted to without departing from the inventive concept or the scope of the appended claims.

What I claim is:

1. In a tool holder for useinturret lathe and with a reamer, a shank for insertion in said turret and provided with a disk-like concentric head and means to mount said collet on said bar to float thereon. a

2. In a tool holder for use in turret lathe and with a reamer, a shank for insertion in said turret and provided with a disk-like concentric head on one end thereof having a front face perpendicular to the axis of said shank, a bar fitting flat against said face to extend across the same, and having a longitudinally arcuate front face and side edgesconverging toward said face, a center extending forwardly from said bar centrally thereof for insertion in a hole to be reamed to thereby axially align the bar with saidhole, means to fasten said bar to said head in axially aligned position, a collet for holding a reamer' with the tail end on said center, said collet interfitting with the front face and sides of said bar, and means to mount said collet on said bar to float thereon, the first-mentioned means comprising a clamping ring threaded onto said head and confining the ends of said bar between the same and said face of the head, said last-mentioned means comprising a lateral slotted flange on said collet, and screws extending through the slots of said flange into said head.

JOSEPH A. HOWARD. 

